Solve the system of equations by any method. \[ \begin{array}{r}-2 x+5 y=-21 \\ 7 x+2 y=15\end{array} \] Enter the exact answer as an ordered pair, ( \( x, y \) ). If there is no solution, enter NS. If there is an infinite number of solutions, enter the general solut an ordered pair in terms of \( x \). Include a multiplication sign between symbols. For example, \( a * x \). I ?

Solve the system of equations \( -2x+5y=-21;7x+2y=15 \). Solve the system of equations by following steps: - step0: Solve using the substitution method: \(\left\{ \begin{array}{l}-2x+5y=-21\\7x+2y=15\end{array}\right.\) - step1: Solve the equation: \(\left\{ \begin{array}{l}x=\frac{21+5y}{2}\\7x+2y=15\end{array}\right.\) - step2: Substitute the value of \(x:\) \(7\times \frac{21+5y}{2}+2y=15\) - step3: Simplify: \(\frac{7\left(21+5y\right)}{2}+2y=15\) - step4: Multiply both sides of the equation by LCD: \(\left(\frac{7\left(21+5y\right)}{2}+2y\right)\times 2=15\times 2\) - step5: Simplify the equation: \(147+39y=30\) - step6: Move the constant to the right side: \(39y=30-147\) - step7: Subtract the numbers: \(39y=-117\) - step8: Divide both sides: \(\frac{39y}{39}=\frac{-117}{39}\) - step9: Divide the numbers: \(y=-3\) - step10: Substitute the value of \(y:\) \(x=\frac{21+5\left(-3\right)}{2}\) - step11: Calculate: \(x=3\) - step12: Calculate: \(\left\{ \begin{array}{l}x=3\\y=-3\end{array}\right.\) - step13: Check the solution: \(\left\{ \begin{array}{l}x=3\\y=-3\end{array}\right.\) - step14: Rewrite: \(\left(x,y\right) = \left(3,-3\right)\) The solution to the system of equations is \( (x, y) = (3, -3) \).